290 likes | 456 Views
La Trobe University 29 June 2006. Reaching interstate consensus - Recent challenges and lessons from the MDBC. Bob Douglas Director, Water Policy Coordination Murray-Darling Basin Commission. Australia’s Murray-Darling Basin. 1.06 million sq. km 15% land mass
E N D
La Trobe University 29 June 2006 Reaching interstate consensus - Recent challenges and lessons from the MDBC Bob Douglas Director, Water Policy Coordination Murray-Darling Basin Commission
Australia’s Murray-Darling Basin • 1.06 million sq. km • 15% land mass • 6.1% of Australia’s total run off • major river system • 2 million people • 2 capital cities
Australia’s Murray-Darling Basin • highly modified environment • extremes in climatic variability • environmentally significant • economically and socially important
Ratioof maximum annual flowto minimum annual flowfor selected rivers
MDB rainfall variability(480mm annual average) River Murray system showing extended drought periods
Environmentally significant • large ecological range – alpine to rainforest to arid • numerous reserves, national parks • 16 RAMSAR sites • world heritage convention listings • internationally important biosphere reserves • breeding grounds for migratory birds • at least 35 endangered birds • at least 16 endangered mammals
Economic importance • 40% of Australian agriculture • approx $14 billion • 70% of irrigated agriculture • approx $7 billion • Tourism • Manufacturing (food processing) • Mining • Rural Communities
Highly regulated river system • $2 billion infrastructure • resource sharing/ allocations • high levels of climatic variability • water flows • impacts of river regulation
Murray-Darling Basin Commission • Murray-Darling Basin Agreement • 6 governments working together • Charter "to promote and co-ordinate effective planning and management for the equitable efficient and sustainable use of the water, land and other environmental resources of the Murray-Darling Basin."
SIX GOVERNMENTS Aust Gov. NSW Vic SA Qld ACT Community Advisory Committee MURRAY-DARLING BASIN MINISTERIAL COUNCIL MURRAY-DARLING BASIN COMMISSION Living Murray Committee Natural Resources Management Committee Commission Strategy Committee River Murray Water Committee MDBC Office
Major Challenges for the MDBC • coordination between 6 govts • sharing the water • highly regulated system • 5 jurisdictions • industries, environment, communities • managing as one catchment • synergies between strategies • implementing The Living Murray • major risks to shared water resources
The Cap Growth of surface water use inMurray-Darling Basin
Risks to shared water resources • number of risk factors may reduce annual surface flows in the MDB by about 20% over the next 20 years. • also impact on • flow regime • water quality and • water security • impact is uncertain • estimated reduction in water volume between 2,500GL and 5,500 GL in 20 years • (average annual flow ~ 14,700 GL)
Risks to shared water resources • climate change • growth in dams • increased groundwater use • reduction in return flows from irrigation • reforestation/ land use change • bushfires
Climate change • estimated largest and most likely reduction in flow • increase the other risks • potentially reduce stream flow by • 1,100 GL in 10 years (5% of annual flow) • 3,300 GL in 50 years (15% of annual flow) Predicted regional differences in percentage reductions in annual stream flow. Dark red indicates greatest reductions. (Source: Jones and Brooke).
Growth in Dams • impact on water volume second to climate change • evidence suggesting number and size of farm dams increased significantly in last 10 years • estimated total streamflow reduction by • 250 to 3,000 GL / year in 20 years • 400 to 4,000 GL/ year in 50 years • future impact depends on effectiveness of legislation or policies
Source: Groundwater Status Report 1990-2000 Groundwater systems • constitutes 10-15% of water used • significant growth in groundwater use • connectivity • may threaten surface water availability • consistency in defining sustainable yield
Reduction in return flows in irrigation • water diverted for irrigation losses through leakage and evaporation • flows back to river and groundwater systems if not used • more efficient water use • reduced flows back to stream • could increase salinity
Source: BRS Reforestation/ land use change • plantations potentially reduce water yield in a catchment • productive forestry areas tend to have water yield impacts • reduction in water flow depends on plantations location and size Increase of plantation forestry in Australia (current and trajectory) towards the 2020 Vision.
Bushfires • bushfires in 2003 affected high rainfall areas in MDB catchment • severe fires have long term effects • affect water quality and reduce surface and groundwater levels • climate change ↑ frequency and intensity of dry periods = ↑ bushfires Variation in run-off from Mountain Ash forests. (source: Kuczera)
Estimated impact Estimated impact of the six risks on Murray-Darling Basin surface water by 2020. Darkest colours show most likely impact (Source: MDBC)
Shared water resources Water shared between jurisdictions (includes both groundwater and surface water)
Framework • need to consider the risks together in an integrated and adaptive way • understand the interrelationships of the various activities and processes and effect on water quantity and quality in the Basin • working with the jurisdictions to address the risks requires • collaboration • building on and enhancing the actions already being taken by individual jurisdictions • identifying where value can be added by a more integrated and collaborative approach • ensuring there is adequate commitment and resources within the jurisdictions
Michael Bell www.mdbc.gov.au
1 Independent President + 2 Federal 2 Qld 2 NSW 2 SA 1 ACT 2 Vic